Plastic Waste and Urban Flooding: An Overlooked Challenge in Kathmandu
Improperly managed single-use plastics and microplastics are higher in urban areas, which ends up by getting mixed with waterbodies and drainage systems. People living in Kathmandu are facing environmental issues related with waste and its consequences during monsoon season. Major scenarios that are frequently observed in such timeframe including overflowing drains, waterlogging in roads, flooded roads, high traffic and disruption of everyday life due to severe rainfall and serious flooding. Heavy rainfall is considered as the major factor for causing urban flooding during rainy season. However, important factor that has been frequently overlooked during the present scenario is plastic waste that are dumped randomly in the road and surrounding environment which is blocking the drainage system. The way we segregate, manage and dispose our waste in any area has a direct impact on how the city or any urban area responds to rainfall.
In case of Kathmandu, a structured drainage network has been designed during city planning phase to manage rainwater by carrying it way from roads, houses, hotels, hospitals, apartments, including different public spaces. However, increasing population density, rapid urbanization and poor waste management have put on the immense pressure on this system. Waste materials like plastic bags, food wrappers, bottles, packaging materials and single-use plastic items are commonly discarded on streets, drainage channels, riverbanks and open areas. During the time of rainfall, these materials are washed away into drains and culverts, where they collect and block the natural flow of water.
The effects are clearly visible across different parts of the Kathmandu during every monsoon season. This year, Nepal, including Kathmandu has also experienced unusually heavy rainfall during pre-monsoon season which led to sudden waterlogging at roads, heavy traffic disruption and difficulties for daily commuters, even before the beginning of official monsoon season. This has led to bigger impacts in the environment. City areas such as Kalanki, Balkhu, Koteshwor, Tinkune, Baneshwor, Maitighar and other low-lying zones of Kathmandu Valley have also faced severe waterlogging problem after heavy rainfall. This situation has not only been experienced during this year’s pre-monsoon period, but has also remained a frequently occurring problem during the monsoon period as well, significantly disrupting the daily life of people and increasing risks to public health of such reason which results in spreading of water related diseases in human health. In many cases, the problem has not only been the amount of rainfall but also the inability of blocked drains to drain water from drainage system effectively. Even a small amount of plastic waste can trap other debris and can create a blockage large enough causing flooding in urban spaces.
The impacts of blocked drains then start to expand and go beyond the flooded roads, eventually disrupts the transportation system of that area. When water remains stagnant in public spaces and around homes, it creates a favorable environment for mosquitoes to breed which increases the risk of diseases like dengue in human health. This has become the major public health concern in Kathmandu since a long time. Floodwater that gets mixed with waste and sewage can further expose communities living nearby to various health related issues. In addition, plastic waste and other debris that are carried through drainage channels often ends up reaching the Bagmati River and its tributaries, contributing to river pollution which impacts negatively by affecting aquatic life and the overall health of these ecosystems.
These issues cannot be solved by government and organizations working on these issues alone. To solve these environmental problems, individual behavior plays an important role. Improper segregation of waste, poor waste collection technique, throwing of plastic debris , wrappers, bottles and other discarded waste haphazardly, lack of enough public waste bins, weak law enforcement and low awareness on waste management among people contribute to the serious problem. Therefore, reducing urban flooding requires both responsible public behavior and stronger action from local authorities along with the government. This includes solutions like proper management of waste at home and landfills, reduction of single-use plastics, regular cleaning of drainage channel by concerned authority and community clean-up efforts, especially before and during the monsoon season.
Climate change is expected to increase extreme rainfall even in both during dry and rainy seasons, making Kathmandu more vulnerable to experience severe flooding in the future. Although rainfall cannot be controlled, but its impacts can be reduced through collective action. Building a flood-resilient Kathmandu requires a shift in how waste is understood and managed in our everyday life. Clean drainage systems are not only the responsibility of municipalities, it also depends on consistent responsible behavior from every household, business and individual. Starting from small actions from individual side such as proper disposal of plastics and other type of wastes, avoiding littering in streets, rivers and public areas and actively supporting all kinds of environmental initiatives can collectively make a huge difference to the environment. If these practices are not strengthened now, the combined pressure of climate change and unmanaged waste will continue to intensify urban flooding risks in the near future.